Heat oven to 350°F. Line 8-inch square baking pan with aluminum foil, extending over edges. Grease and flour foil; set aside.
Place 1/2 cup dark chocolate chips and butter in bowl. Microwave 1-2 minutes, stirring every 30 seconds, or until chips are melted. Stir until smooth.
Combine sugar and eggs in bowl. Beat at medium speed until thick and smooth. Add melted chocolate mixture; continue beating until smooth. Stir in flour and remaining 1/4 cup dark chocolate chips just until mixed.
Spread batter into prepared pan. Bake 18-22 minutes or until edges are set and center appears soft. Do not over bake. Cool completely.
Place semi-sweet chocolate chips into bowl. Heat whipping cream in saucepan over medium heat 3-4 minutes or until whipping cream just comes to a boil. Pour warm cream over chocolate chips; let stand 1 minute. Stir until smooth. Cool. Spread over cooled bars.
Drop 8 small portions of melted white chocolate randomly over glaze. Pull knife through white chocolate to create design. Cover; refrigerate at least 2 hours or until serving time.
Carefully lift bars out of pan using foil ends. Cut into bars using sharp knife. If necessary, wipe knife occasionally.
Place small bars into paper mini baking cups to serve. Store leftover bars in refrigerator.